SA's are never a guarantee. The skills are proggrammed in hidden mode, and a player can be better in corners without show any SA of corners... and a player wth SA of corners, can be in hidden proggramming % worst programmed.
When season starts one have to do friendlies and prove in fouls and corners 2 players (1 right 1 left and see because in every season there is a pleyer with more chances than the others)... and formation... mate you have to read my Bayern team page and read the section of team phillosophy :P
But a 4-3-1-2 is a very good formation, and the AMC can be a MC or ST without problems of any penalty in possession bonus.